3results about How to "Reduce current amplitude" patented technology

The invention provides a capacitor voltage fluctuation suppression method for a modular multi-level matrix converter, and the method comprises the steps: obtaining the capacitor voltage and current of each bridge arm of an M3C under a double alpha beta 0 coordinate system, calculating the three-phase reference voltage of the input side and the output side of the M3C according to the type of an AC system connected with the two sides of the M3C, and carrying out the calculation of the three-phase reference voltage of the input side and the output side of the M3C; the basic output reference voltage of the bridge arm is determined; calculating an injectable common-mode voltage range, and determining a reference value of the injected common-mode voltage; calculating a ring current reference value required for balancing the capacitor voltage, and obtaining a ring current voltage reference value through closed-loop control; the loop current reference voltage of each bridge arm is calculated through inverse double alpha beta 0 conversion, the total bridge arm output reference voltage is obtained by combining the bridge arm basic output reference voltage and the common-mode voltage reference value, the control of the output voltage of each bridge arm is realized through modulation, and a driving signal of a switching device is generated. Compared with a conventional high-frequency sine common-mode injection method, the method can effectively reduce the capacitor voltage fluctuation, and reduces the current amplitude of a bridge arm.

The present invention discloses a seven-level inverter circuit and a control method thereof. The seven-level inverter circuit comprises: an input DC power supply, a low-frequency pole-changing bridge arm, a high-frequency level selection bridge arm, an inverter-side inductor and a filter capacitor; by controlling the on-off of a switch tube, the inverter bridge arm composed of two bridge arms can output 0, V dc / 4, V dc / 2, V dc ,‑V dc / 4, ‑V dc / 2, ‑V dc Seven levels; the present invention controls the amount of charge to make the seven-level inverter circuit work in a mixed conduction mode (CCM and TPCM). The seven-level inverter circuit works at a fixed frequency and works in fixed-frequency critical continuous conduction in TPCM, which can significantly reduce the amplitude of the inductor current on the inverter side, that is, reduce the conduction loss of the seven-level inverter circuit, and effectively improve the low-frequency distortion of the output current.

The utility model discloses a reverse flow detection circuit and a power supply device, which are used for meeting the reverse flow fault detection requirement of equipment in a high-power power supply scene and reducing the cost of the reverse flow detection device. The backward flow detection circuit comprises a mutual inductor, an impedance module and an amplifier. A primary winding of the mutual inductor is used for being connected with a to-be-tested branch, and a secondary winding of the mutual inductor is connected with the impedance module; the impedance module is connected with the processing device through the amplifier; and the amplifier is used for amplifying the electrical parameters output by the impedance module and then outputting the electrical parameters to the processing device, so that the processing device performs backward flow fault detection according to the electrical parameters output by the amplifier. As the impedance module used for limiting the current is additionally arranged on the secondary side of the mutual inductor, when the reverse irrigation detection circuit is applied to a high-power power supply scene, the amplitude of the secondary current output by the mutual inductor can also be limited within a small range, and safe operation of a rear-end connecting device is ensured.